java - Android ListView - 单击即可转至网站

Question

抱歉，如果问题有点新闻类型，但 Android 不了解我:(

所以我有填充 TextView 的 MainActivity.Java。我使用 JSON 从服务器获取数据，它提供了 id、用户名、消息、日期时间、状态、类型等参数。我想要的是每次点击列表项时，它都会进入网站，如下所示:

http://my_web_site_url/json?id=id_of_the_list_item&status=something

即，当用户单击单个列表项时，URL 会使用 JSON 检索到的每个列表项的相同 ID 进行重定向。

如何设置并获取每个list_item_id以及如何访问网站？

感谢任何帮助!

我的代码是:

package something;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;

public class MainActivity extends AppCompatActivity {

private String TAG = MainActivity.class.getSimpleName();

private ProgressDialog pDialog;
private ListView lv;

// URL to get contacts JSON
private static String url = "my_website_that_returns_json_data";

ArrayList<HashMap<String, String>> contactList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    contactList = new ArrayList<>();

    lv = (ListView) findViewById(R.id.list);
    new GetContacts().execute();
}

/**
 * Async task class to get json by making HTTP call
 */
private class GetContacts extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Showing progress dialog
        pDialog = new ProgressDialog(MainActivity.this);
        pDialog.setMessage("Please wait...");
        pDialog.setCancelable(false);
        pDialog.show();

    }

    @Override
    protected Void doInBackground(Void... arg0) {
        HttpHandler sh = new HttpHandler();

        // Making a request to url and getting response
        String jsonStr = sh.makeServiceCall(url);

        Log.e(TAG, "Response from url: " + jsonStr);

        if (jsonStr != null) {
            try {
                JSONObject jsonObj = new JSONObject(jsonStr);

                // Getting JSON Array node
                JSONArray result = jsonObj.getJSONArray("result");

                // looping through All Contacts
                for (int i = 0; i < result.length(); i++) {
                    JSONObject c = result.getJSONObject(i);

                    String id = c.getString("id");
                    String username = c.getString("username");
                    String message = c.getString("message");
                    String date_status = "Date: " + c.getString("date_time") + "    Status: " + c.getString("status");


                    // tmp hash map for single contact
                    HashMap<String, String> result1 = new HashMap<>();

                    // adding each child node to HashMap key => value
                    result1.put("id", id);
                    result1.put("username", username);
                    result1.put("message", message);
                    result1.put("date_status", date_status);

                    // adding contact to contact list
                    contactList.add(result1);
                }
            } catch (final JSONException e) {
                Log.e(TAG, "Json parsing error: " + e.getMessage());
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Json parsing error: " + e.getMessage(),
                                Toast.LENGTH_LONG)
                                .show();
                    }
                });

            }
        } else {
            Log.e(TAG, "Couldn't get json from server.");
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getApplicationContext(),
                            "Couldn't get json from server. Check LogCat for possible errors!",
                            Toast.LENGTH_LONG)
                            .show();
                }
            });

        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        // Dismiss the progress dialog
        if (pDialog.isShowing())
            pDialog.dismiss();
        /**
         * Updating parsed JSON data into ListView
         * */

        ListAdapter adapter = new SimpleAdapter(
                MainActivity.this, contactList,
                R.layout.list_item, new String[]{"username", "message",
                "date_status"}, new int[]{R.id.username,
                R.id.message,R.id.date_status});

        lv.setAdapter(adapter);

    }

}
}

Answer 1

在 ListView 中使用 onItemClickListener

使用内部类的示例

 lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick((AdapterView<?> parent, 
            View view, 
            int position, 
            long id)) {


        String item = lv.getItemAtPosition(position);
        Toast.makeText(this,"You selected : " + item,Toast.LENGTH_SHORT).show();


        }
    });

在您的方法中，您将获得数据的位置并加载链接。